SAP智力题-----A bum in wine cellars ★★★★★★★

There are 9 wine cellars located side by side in a street, a bum is hiding in one of of them. Everyday he would drink one bottle of wine and leave the empty bottle on the ground. Everynight, he will move to an adjacent cellar. From the day he begins to hide, the police begin to search, everyday they will search one cellar. How many days are necessary and sufficient to find the bum?
----Designed by Hansen Chen in 2008( https://www.sdn.sap.com/irj/scn/forum?forumID=410 )

I got the inspiration from a puzzle called "burglar in rooms", it is much more challenging by adding the bottle to the logic.

If you can solve this puzzle, try to consider an extended one: ★★★★★★★★
There are 999 wine cellars located side by side in a street, a bum is hiding in one of of them. Everyday he would drink one bottle of wine and leave the empty bottle on the ground. Everynight, he will move to an adjacent cellar. From the day he begins to hide, the police begin to search, everyday they will search one cellar.
1. how to find the bum in less than 1020 days?
2. how to find the bum in less than 999 days?
(The extended one is not as time-consumming as imagined. And the strategy is totally different from the 9-cellar one.)

所有跟帖： 

• 回复：SAP智力题-----A bum in wine cellars ★★★★★★★ -iooooooi- ♂ (463 bytes) () 08/21/2009 postreply 08:48:23

• Also, does the bum aware which cellar the police searched the da -iooooooi- ♂ (335 bytes) () 08/21/2009 postreply 08:58:48

• My understanding of the problem -dynamic- ♂ (1229 bytes) () 08/21/2009 postreply 14:46:53

• 回复：SAP智力题-----A bum in wine cellars ★★★★★★★ -panzertiger503- ♂ (140 bytes) () 09/01/2009 postreply 12:40:06

• I am wrong -panzertiger503- ♂ (148 bytes) () 09/01/2009 postreply 12:59:45